fix: package.json & package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-MONGODB-473855
- https://snyk.io/vuln/SNYK-JS-MONGOOSE-472486

Author: snyk-bot

package-lock.json

@@ -6,7 +6,7 @@
   "license": "MIT",
   "dependencies": {
     "@hapi/hapi": "^18.4.0",
-    "mongoose": "^4.13.19"
+    "mongoose": "^5.7.5"
   },
   "devDependencies": {},
   "scripts": {